Electrical connection configurations for privacy glazing structures

ABSTRACT

A privacy glazing structure may include an electrically controllable optically active material that provides controlled transition between a privacy or scattering state and a visible or transmittance state. To make electrical connections with electrode layers that control the optically active material, the privacy glazing structure may include electrode engagement regions. In some examples, the electrode engagement regions are formed as notches in peripheral edges of opposed panes bounding the optically active material. The notches may or may not overlap to provide a through conduit in the region of overlap for wiring. In either case, the notches may allow the remainder of the structure to have a flush edge surface for ease of downstream processing.

This application claims the benefit of U.S. Provisional PatentApplication No. 62/532,154, filed Jul. 13, 2017, the entire contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to structures that include an electricallycontrollable optically active material and, more particularly, toelectrical connection configurations for glazing structures that includean electrically controllable optically active material.

BACKGROUND

Windows, doors, partitions, and other structures having controllablelight modulation have been gaining popularity in the marketplace. Thesestructures are commonly referred to as “smart” structures or “privacy”structures for their ability to transform from a transparent state inwhich a user can see through the structure to a private state in whichviewing is inhibited through the structure. For example, smart windowsare being used in high-end automobiles and homes and smart partitionsare being used as walls in office spaces to provide controlled privacyand visual darkening.

A variety of different technologies can be used to provide controlledoptical transmission for a smart structure. For example, electrochromictechnologies, photochromic technologies, thermochromic technologies,suspended particle technologies, and liquid crystal technologies are allbeing used in different smart structure applications to providecontrollable privacy. The technologies generally use an energy source,such as electricity, to transform from a transparent state to a privacystate or vice versa.

In instances where controlled transmission is provided throughapplication or removal of electrical energy, the optical transmissionstructure can include electrode contacts where electrical wiringinterfaces with electrodes that control the optically controllablemedium. To provide space on the structure needed to implement theelectrode contacts, one substrate bounding the optically controllablemedium may be offset from an opposite substrate, providing an offset lipwhere a bus bar can be installed. While effective to establishelectrical contact, this offset structure can project into the sightline of the structure and be difficult to manipulate during furtherprocessing because of the irregular, offset surface.

SUMMARY

In general, this disclosure is directed to privacy structuresincorporating an electrically controllable optically active materialthat provides controllable privacy. The term privacy structure includesprivacy cells, privacy glazing structures, smart cells, smart glazingstructure, and related devices that provide controllable opticalactivity and, hence, visibility through the structure. Such structurescan provide switchable optical activity that provides controllabledarkening, controllable light scattering, or both controllable darkeningand controllable light scattering. Controllable darkening refers to theability of the optically active material to transition between a highvisible light transmission state (a bright state), a low visible lighttransmission dark state, and optionally intermediate statestherebetween, and vice versa, by controlling an external energy sourceapplied to the optically active material. Controllable light scatteringrefers to the ability of the optically active material to transitionbetween a low visible haze state, a high visible haze state, andoptionally intermediate states therebetween, and vice versa, bycontrolling an external energy source. Thus, reference to the terms“privacy” and “privacy state” in the present disclosure does notnecessarily require complete visible obscuring through the structure(unless otherwise noted). Rather, different degrees of privacy orobscuring through the structure may be achieved depending, e.g., on thetype of optically active material used and the conditions of theexternal energy source applied to the optically active material.

A privacy structure according to the disclosure can be implemented inthe form of a window, door, skylight, interior partition, or yet otherstructure where controllable visible transmittance is desired. In anycase, the privacy structure may be fabricated from multiple panes oftransparent material that include an electrically controllable mediumbetween the panes. Each pane of transparent material can carry anelectrode layer, which may be implemented as a layer of electricallyconductive and optically transparent material deposited over the pane.The optically active material may be controlled, for example via anelectrical driver communicatively coupled to the electrode layers, bycontrolling the application and/or removal of electrical energy to theoptically active material. For example, application and/or removal ofelectrical energy from the optically active material can cause theoptically active material to transition from a scattering state in whichvisibility through the structure is inhibited to a transparent state inwhich visibility through the structure is comparatively clear.

To provide electrical contact between the electrode layers carried bythe panes of transparent material, each pane may include a notch formedfrom a peripheral edge surface inward toward a center of the pane. Thenotch may be a groove or cut into the peripheral edge of the pane thatdefines a carve-out devoid of material. The notch can provide access toan underlying electrode layer. For example, the notch formed on a panebounding one side of the optically active material can provide access tothe electrode layer on the opposite pane and vice versa. Electricalwiring that supplies electrical energy to control the optically activematerial can be connected to each electrode layer through acorresponding notch.

While each pane may include a notch for making connection with anunderlying electrode layer, the panes bounding the optically activematerial may themselves be joined together to provide a flush edgesurface. For example, the panes bounding the optically active material,once joined together, may form a common edge surface with the peripheraledges of joined sheets being substantially co-planar. As a result, thepanes bounding the optically active material may form a common,substantially planar edge that is generally orthogonal to the outerfaces of the panes, e.g., without having the peripheral edge of one paneoffset relative to the peripheral edge of another pane.

Configuring an optical structure with electrical connection regions thatare recessed relative to a flush edge surface may be useful for avariety of reasons. First, configuring the optical structure with aflush edge can be useful to facilitate transport of the structure (e.g.,on a conveyor line and/or conveyor rolls) for downstream processing thatis challenging if one pane is offset relative to another pane. Second,in applications where a frame or sash (e.g., window or door frame orsash) is positioned around the optical structure, the flush edge surfacecan minimize or eliminate the extent to which the electrode connectionregion of the optical structure projects out of the frame or sash andinto the slight line through which an external observer looks throughthe structure. Additionally, configuring an optical structure withelectrical connection regions that are recessed relative to a flush edgemay facilitate improved sealing around the optical structure, helping toprevent ingress of environmental contaminants into the structure.

The notches formed into the panes of transparent material to provide theelectrical connection locations for the electrode layers can have avariety of different configurations. In some examples, the notches onopposed transparent panes arranged to partially but not fully overlapthrough the cross-section of the optical structure. As a result, aconduit may be formed through the entire thickness of the opticalstructure where the notches overlap. This conduit can provide an openingthrough which electrical wiring can be positioned to connect differentelectrode layers to an electrical source. For examples, rather thanrunning wires to each electrode layer along both sides of the opticalstructure, the wiring may be run along a single side of the structure.Multiple wires can enter the conduit through one side of the conduit,with one wire bending approximately 90 degrees to connect to a firstelectrode layer and a another wire bending approximately 180 degrees toconnect to a second electrode layer. Other configurations of notch andwiring arrangements are possible, and it should be appreciated that thedisclosure is not limited in this respect.

To bond and/or seal opposed panes of transparent material bounding theoptically active material together, a seal material may be positionedaround the perimeter of the panes, e.g., surrounding the opticallyactive material. Without wishing to be bound by any particular theory,it is has been found in some applications that positioning the seal overthe electrode layers of the optical structure such that electricity isconveyed through the seal during operation of the structure has atendency to accelerate degradation of the seal. Accordingly, in someconfigurations, the electrode layers on the optical structure are offsetfrom the peripheral edge of the transparent panes about which the sealextends. For example, the electrode layers may be removed (e.g. viagrinding or laser ablation) such that the perimeter region over whichthe seal extends is devoid of one or both electrode layers and/or theelectrode layers are otherwise deactivated in the region. To provideelectrical connection, however, one or both electrode layers may have acontact portion that extends into the otherwise deactivated perimeterregion, e.g., to the perimeter edge. The contact portion may bepositioned to underlie a notch of an overlying transparent pane, therebyproviding an electrically active location for electrically connectingthe electrode layer with a power source.

In one example, a privacy glazing structure is described that includes afirst pane of transparent material, a second pane of transparentmaterial, a first electrode layer, and a second electrode layer. Thefirst pane of transparent material has an inner face, an outer face, anda peripheral edge. The second pane of transparent material has an innerface, an outer face, and a peripheral edge. The first electrode layer ison the inner face of the first pane of transparent material. The secondelectrode layer is on the inner face of the second pane of transparentmaterial. The structure further includes an electrically controllableoptically active material positioned between the first electrode layeron the inner face of the first pane of transparent material and thesecond electrode layer on the inner face of the second pane oftransparent material. The example specifies that the first pane oftransparent material is generally parallel to the second pane oftransparent material to form a cavity therebetween containing theelectrically controllable optically active material and the peripheraledge of the first pane of transparent material is aligned with theperipheral edge of the second pane of transparent material to provide aflush edge surface. The example further specifies that the first pane oftransparent material defines a first notch providing access to thesecond electrode layer on the inner face of the second pane oftransparent material and the second pane of transparent material definesa second notch providing access to the first electrode layer on theinner face of the first pane of transparent material.

The details of one or more examples are set forth in the accompanyingdrawings and the description below. Other features, objects, andadvantages will be apparent from the description and drawings, and fromthe claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a side view of an example privacy glazing structure.

FIG. 2 is a side view of the example privacy glazing structure of FIG. 1incorporated into a multi-pane insulating glazing unit.

FIG. 3 is a perspective view of an example edge configuration of aprivacy structure that includes electrical connection notches.

FIGS. 4A-4D illustrate example cross-sectional shapes that may be usedfor an electrical connection notch.

FIG. 5 illustrates example notch dimensions that can be used forelectrical connection notches according to the disclosure.

FIG. 6 is a top view illustration showing an example configuration inwhich two notches overlap to form a conduit through a region of overlap.

FIG. 7 is a side view illustrating an example arrangement of featureswhere a first notch overlaps with a second notch.

FIGS. 8A and 8B illustrate example sloped notch wall surfaces that maybe used on a notch according to the disclosure.

FIGS. 9A and 9B are views of example inner surfaces of first and secondpanes showing example electrode layer arrangements that can be used in aprivacy structure according to the disclosure.

FIGS. 10A and 10B are top and side views, respectively, showing anexample single notch electrical configuration according to thedisclosure.

FIGS. 11A-11C illustrate example assembly steps for forming a notch inan edge of a pane of transparent material that does not extend throughthe entire thickness of the material.

FIGS. 12A-12C illustrate example assembly steps for forming a notch anda relief notch in an edge of a pane of transparent material that doesnot extend through the entire thickness of the material.

FIGS. 13A-13C illustrate example assembly steps for forming multiplenotches in an edge of a pane of transparent material.

DETAILED DESCRIPTION

In general, the present disclosure is directed to electrical connectionconfigurations for optical structures having controllable lightmodulation. For example, an optical structure may include anelectrically controllable optically active material that providescontrolled transition between a privacy or scattering state and avisible or transmittance state. To make electrical connections withelectrode layers that control the optically active material, the opticalstructure may include electrode engagement regions. In some examples,the electrode engagement regions are formed as notches in peripheraledges of opposed panes bounding the optically active material. Thenotches may or may not overlap to provide a through conduit in theregion of overlap for wiring. In either case, the notches may allow theremainder of the structure to have a flush edge surface for ease ofdownstream processing.

FIG. 1 is a side view of an example privacy glazing structure 12 thatincludes a first pane of transparent material 14 and a second pane oftransparent material 16 with a layer of optically active material 18bounded between the two panes of transparent material. The privacyglazing structure 12 also includes a first electrode layer 20 and asecond electrode layer 22. The first electrode layer 20 is carried bythe first pane of transparent material 14 while the second electrodelayer 22 is carried by the second pane of transparent material. Inoperation, electricity supplied through the first and second electrodelayers 20, 22 can control the optically active material 18 to controlvisibility through the privacy glazing structure.

As described in greater detail below, the first and second panes oftransparent material 14, 16 may each have an electrical connection notchformed in their edge. The notch may define a cutout that is offset fromthe remainder of the edge. The notch on the first pane 14 can provideaccess to an underlying electrode layer (second electrode layer 22)carried by second pane 16. Similarly, the notch on the second pane 16can provide access to an underlying electrode layer (first electrodelayer 20) carried by first pane 14. While the notches on the first andsecond panes 14, 16 may provide an offset cavity for making electricalconnections, the remainder of the edge of privacy glazing structure maybe substantially flush, e.g., such that there is substantially no offsetbetween the terminal or peripheral edges of the first and second panes14, 16. The electrical connection configuration of privacy glazingstructure 12 can have a variety of different configurations as describedin greater detail herein.

Privacy glazing structure 12 can utilize any suitable privacy materialsfor the layer of optically active material 18. Further, althoughoptically active material 18 is generally illustrated and described asbeing a single layer of material, it should be appreciated that astructure in accordance with the disclosure can have one or more layersof optically active material with the same or varying thicknesses. Ingeneral, optically active material 18 is configured to providecontrollable and reversible optical obscuring and lightening. Opticallyactive material 18 can be an electronically controllable opticallyactive material that changes direct visible transmittance in response tochanges in electrical energy applied to the material.

In one example, optically active material 18 is formed of anelectrochromic material that changes opacity and, hence, lighttransmission properties, in response to voltage changes applied to thematerial. Typical examples of electrochromic materials are WO₃ and MoO₃,which are usually colorless when applied to a substrate in thin layers.An electrochromic layer may change its optical properties by oxidationor reduction processes. For example, in the case of tungsten oxide,protons can move in the electrochromic layer in response to changingvoltage, reducing the tungsten oxide to blue tungsten bronze. Theintensity of coloration is varied by the magnitude of charge applied tothe layer.

In another example, optically active material 18 is formed of a liquidcrystal material. Different types of liquid crystal materials that canbe used as optically active material 18 include polymer dispersed liquidcrystal (PDLC) materials and polymer stabilized cholesteric texture(PSCT) materials. Polymer dispersed liquid crystals usually involvephase separation of nematic liquid crystal from a homogeneous liquidcrystal containing an amount of polymer, sandwiched between electrodelayers 20 and 22. When the electric field is off, the liquid crystalsmay be randomly scattered. This scatters light entering the liquidcrystal and diffuses the transmitted light through the material. When acertain voltage is applied between the two electrode layers, the liquidcrystals may homeotropically align and the liquid crystals increase inoptical transparency, allowing light to transmit through the crystals.

In the case of polymer stabilized cholesteric texture (PSCT) materials,the material can either be a normal mode polymer stabilized cholesterictexture material or a reverse mode polymer stabilized cholesterictexture material. In a normal polymer stabilized cholesteric texturematerial, light is scattered when there is no electrical field appliedto the material. If an electric field is applied to the liquid crystal,it turns to the homeotropic state, causing the liquid crystals toreorient themselves parallel in the direction of the electric field.This causes the liquid crystals to increase in optical transparency andallows light to transmit through the liquid crystal layer. In a reversemode polymer stabilized cholesteric texture material, the liquidcrystals are transparent in the absence of an electric field (e.g., zeroelectric field) but light scattering upon application of an electricfield.

In one example in which the layer of optically active material 18 isimplemented using liquid crystals, the optically active materialincludes liquid crystals and a dichroic dye to provide a guest-hostliquid crystal mode of operation. When so configured, the dichroic dyecan function as a guest compound within the liquid crystal host. Thedichroic dye can be selected so the orientation of the dye moleculesfollows the orientation of the liquid crystal molecules. In someexamples, when an electric field is applied to the optically activematerial 18, there is little to no absorption in the short axis of thedye molecule, and when the electric field is removed from the opticallyactive material, the dye molecules absorb in the long axis. As a result,the dichroic dye molecules can absorb light when the optically activematerial is transitioned to a scattering state. When so configured, theoptically active material may absorb light impinging upon the materialto prevent an observer on one side of privacy glazing structure 12 fromclearly observing activity occurring on the opposite side of thestructure.

When optically active material 28 is implemented using liquid crystals,the optically active material may include liquid crystal moleculeswithin a polymer matrix. The polymer matrix may or may not be cured,resulting in a solid or liquid medium of polymer surrounding liquidcrystal molecules. In addition, in some examples, the optically activematerial 18 may contain spacer beads (e.g., micro-spheres), for examplehaving an average diameter ranging from 3 micrometers to 40 micrometers,to maintain separation between the first pane of transparent material 14and the second pane of transparent material 16.

In another example in which the layer of optically active material 18 isimplemented using a liquid crystal material, the liquid crystal materialturns hazy when transitioned to the privacy state. Such a material mayscatter light impinging upon the material to prevent an observer on oneside of privacy glazing structure 12 from clearly observing activityoccurring on the opposite side of the structure. Such a material maysignificantly reduce regular visible transmittance through the material(which may also be referred to as direct visible transmittance) whileonly minimally reducing total visible transmittance when in the privacystate, as compared to when in the light transmitting state. When usingthese materials, the amount of scattered visible light transmittingthrough the material may increase in the privacy state as compared tothe light transmitting state, compensating for the reduced regularvisible transmittance through the material. Regular or direct visibletransmittance may be considered the transmitted visible light that isnot scattered or redirected through optically active material 18.

Another type of material that can be used as the layer of opticallyactive material 18 is a suspended particle material. Suspended particlematerials are typically dark or opaque in a non-activated state butbecome transparent when a voltage is applied. Other types ofelectrically controllable optically active materials can be utilized asoptically active material 18, and the disclosure is not limited in thisrespect.

Independent of the specific type of material(s) used for the layer ofoptically active material 18, the material can change from a lighttransmissive state in which privacy glazing structure 12 is intended tobe transparent to a privacy state in which visibility through theinsulating glazing unit is intended to be reduced. Optically activematerial 18 may exhibit progressively decreasing direct visibletransmittance when transitioning from a maximum light transmissive stateto a maximum privacy state. Similarly, optically active material 18 mayexhibit progressively increasing direct visible transmittance whentransitioning from a maximum privacy state to a maximum transmissivestate. The speed at which optically active material 18 transitions froma generally transparent transmission state to a generally opaque privacystate may be dictated by a variety factors, including the specific typeof material selected for optically active material 18, the temperatureof the material, the electrical voltage applied to the material, and thelike.

Depending on the type of material used for optically active material 18,the material may exhibit controllable darkening. As noted above,controllable darkening refers to the ability of the optically activematerial to transition between a high visible light transmission state(a bright state), a low visible light transmission dark state, andoptionally intermediate states therebetween, and vice versa, bycontrolling an external energy source applied to the optically activematerial. When optically active material 18 is so configured, thevisible transmittance through the cell containing optically activematerial 18 (e.g., in addition to other substrates and/or laminatelayers bounding the optically active material and forming the cell) maybe greater than 40% when optically active material 22 is transitioned tothe high visible transmission state light state, such as greater than60%. By contrast, the visible transmittance through the cell may be lessthan 5 percent when optically active material 18 is transitioned to thelow visible light transmission dark state, such as less than 1%. Visibletransmittance can be measured according to ASTM D1003-13.

Additionally or alternatively, optically active material 18 may exhibitcontrollable light scattering. As noted above, controllable lightscattering refers to the ability of the optically active material totransition between a low visible haze state, a high visible haze state,and optionally intermediate states therebetween, and vice versa, bycontrolling an external energy source. When optically active material 18is so configured, the transmission haze through the cell containingoptically active material 18 may be less than 10% when optically activematerial 18 is transitioned to the low visible haze state, such as lessthan 2%. By contrast, the transmission haze through the cell may begreater than 85% when optically active material 18 is transitioned tothe high visible haze state and have a clarity value below 50%, such asa transmission haze greater than 95% and a clarity value below 30%.Transmission haze can be measured according to ASTM D1003-13. Claritycan be measured using a BYK Gardener Haze-Gard meter, commerciallyavailable from BYK-GARDNER GMBH.

To electrically control optically active material 18, privacy glazingstructure 12 in the example of FIG. 1 includes first electrode layer 20and second electrode layer 22. Each electrode layer may be in the formof an electrically conductive coating deposited on or over the surfaceof each respective pane facing the optically active material 18. Forexample, first pane of transparent material 14 may define an innersurface 24A and an outer surface 24B on an opposite side of the pane.Similarly, second pane of transparent material 16 may define an innersurface 26A and an outer surface 26B on an opposite side of the pane.First electrode layer 20 can be deposited over the inner surface 24A ofthe first pane, while second electrode layer 22 can be deposited overthe inner surface 26A of the second pane. The first and second electrodelayers 20, 22 can be deposited directed on the inner surface of arespective pane or one or more intermediate layers, such as a blockerlayer, and be deposited between the inner surface of the pane and theelectrode layer.

Each electrode layer 20, 22 may be an electrically conductive coatingthat is a transparent conductive oxide (“TCO”) coating, such asaluminum-doped zinc oxide and/or tin-doped indium oxide. The transparentconductive oxide coatings can be electrically connected to a powersource through notch structures as described in greater detail below. Insome examples, the transparent conductive coatings forming electrodelayers 20, 22 define wall surfaces of a cavity between first pane oftransparent material 14 and second pane of transparent material 16 whichoptically active material 18 contacts. In other examples, one or moreother coatings may overlay the first and/or second electrode layers 20,22, such as a dielectric overcoat (e.g., silicon oxynitride). In eithercase, first pane of transparent material 14 and second pane oftransparent material 16, as well as any coatings on inner faces 24A, 26Aof the panes can form a cavity or chamber containing optically activematerial 18.

For example, one or both of the panes of transparent material 14, 16bounding the optically active material can have an alignment layerbounding and contacting optically active material 18. The alignmentlayer can be deposited over any underlying layers carried by the pane,such as an electrode layer, an underlying transparent dielectricblocking layer (e.g., silicone oxide), and/or transparent dielectricovercoat. The alignment layer can help reduce or eliminate Mura(blemish) defects, e.g., by changing the surface energy and/or surfaceinteractions between optically active material 18 and the surface ofpane contacting the optically active material. In one example, thealignment layer is implemented by a layer containing polyimide (e.g.,formed by coating the surface with a coating containing polyimide). Thepolyimide layer may or may not be rubbed to modify the properties of thelayer and corresponding interactions with optically active layer 18.

The panes of transparent material forming privacy glazing structure 12,including first pane 14 and second pane 16, can be formed of anysuitable material. Each pane of transparent material may be formed fromthe same material, or at least one of the panes of transparent materialmay be formed of a material different than at least one other of thepanes of transparent material. In some examples, at least one (andoptionally all) the panes of privacy glazing structure 12 are formed ofglass. In other examples, at least one (and optionally all) the privacyglazing structure 12 are formed of plastic such as, e.g., a fluorocarbonplastic, polypropylene, polyethylene, or polyester. When glass is used,the glass may be aluminum borosilicate glass, sodium-lime (e.g.,sodium-lime-silicate) glass, or another type of glass. In addition, theglass may be clear or the glass may be colored, depending on theapplication. Although the glass can be manufactured using differenttechniques, in some examples the glass is manufactured on a float bathline in which molten glass is deposited on a bath of molten tin to shapeand solidify the glass. Such an example glass may be referred to asfloat glass.

In some examples, first pane 14 and/or second pane 16 may be formed frommultiple different types of materials. For example, the substrates maybe formed of a laminated glass, which may include two panes of glassbonded together with a polymer such as polyvinyl butyral. Additionaldetails on privacy glazing substrate arrangements that can be used inthe present disclosure can be found in U.S. patent application Ser. No.15/958,724, titled “HIGH PERFORMANCE PRIVACY GLAZING STRUCTURES” andfiled Apr. 20, 2018, the entire contents of which are incorporatedherein by reference.

Privacy glazing structure 12 can be used in any desired application,including in a door, a window, a wall (e.g., wall partition), a skylightin a residential or commercial building, or in other applications. Tohelp facilitate installation of privacy glazing structure 12, thestructure may include a frame 30 surrounding the exterior perimeter ofthe structure. In different examples, frame 30 may be fabricated fromwood, metal, or a plastic material such a vinyl. Frame 30 may defines achannel 32 that receives and holds the external perimeter edge ofstructure 12. The sightline through privacy glazing structure 12 isgenerally established as the location where frame 30 ends and visibilitythrough privacy glazing structure 12 begins.

In the example of FIG. 1, privacy glazing structure 12 is illustrated asa privacy cell formed of two panes of transparent material boundingoptically active material 18. In other configurations, privacy glazingstructure 12 may be incorporated into a multi-pane glazing structurethat include a privacy cell having one or more additional panesseparated by one or more between-pane spaces. FIG. 2 is a side view ofan example configuration in which privacy glazing structure 12 from FIG.1 is incorporated into a multi-pane insulating glazing unit having abetween-pane space.

As shown in the illustrated example of FIG. 2, a multi-pane privacyglazing structure 50 may include privacy glazing structure 12 separatedfrom an additional (e.g., third) pane of transparent material 52 by abetween-pane space 54 by a spacer 56. Spacer 56 may extend around theentire perimeter of multi-pane privacy glazing structure 50 tohermetically seal the between-pane space 56 from gas exchange with asurrounding environment. To minimize thermal exchange across multi-paneprivacy glazing structure 50, between-pane space 54 can be filled withan insulative gas or even evacuated of gas. For example, between-panespace 54 may be filled with an insulative gas such as argon, krypton, orxenon. In such applications, the insulative gas may be mixed with dryair to provide a desired ratio of air to insulative gas, such as 10percent air and 90 percent insulative gas. In other examples,between-pane space 54 may be evacuated so that the between-pane space isat vacuum pressure relative to the pressure of an environmentsurrounding multi-pane privacy glazing structure 50.

Spacer 56 can be any structure that holds opposed substrates in a spacedapart relationship over the service life of multi-pane privacy glazingstructure 50 and seals between-pane space 54 between the opposed panesof material, e.g., so as to inhibit or eliminate gas exchange betweenthe between-pane space and an environment surrounding the unit. Oneexample of a spacer that can be used as spacer 56 is a tubular spacerpositioned between first pane of transparent material 14 and third paneof transparent material 52. The tubular spacer may define a hollow lumenor tube which, in some examples, is filled with desiccant. The tubularspacer may have a first side surface adhered (by a first bead ofsealant) to the outer surface 24B of first pane of transparent material14 and a second side surface adhered (by a second bead of sealant) tothird pane of transparent material 52. A top surface of the tubularspacer can exposed to between-pane space 54 and, in some examples,includes openings that allow gas within the between-pane space tocommunicate with desiccating material inside of the spacer. Such aspacer can be fabricated from aluminum, stainless steel, athermoplastic, or any other suitable material. Advantageous glazingspacers are available commercially from Allmetal, Inc. of Itasca, Ill.,U.S.A.

Another example of a spacer that can be used as spacer 56 is a spacerformed from a corrugated metal reinforcing sheet surrounded by a sealantcomposition. The corrugated metal reinforcing sheet may be a rigidstructural component that holds first pane of transparent material 14apart from third pane of transparent material 52. Such a spacer is oftenreferred to in commercial settings as swiggle spacer. In yet anotherexample, spacer 56 may be formed from a foam material surrounded on allsides except a side facing a between-pane space with a metal foil. Sucha spacer is commercially available from Edgetech under the trade nameSuper Spacer®. As another example, spacer 56 may be a thermoplasticspacer (TPS) spacer formed by positioning a primary sealant (e.g.,adhesive) between first pane of transparent material 14 and third paneof transparent material 52 followed, optionally, by a secondary sealantapplied around the perimeter defined between the substrates and theprimary sealant. Spacer 56 can have other configurations, as will beappreciated by those of ordinary skill in the art.

Depending on the application, first patent of transparent material 14,second pane of transparent material 16, and/or third pane of transparentmaterial 52 (when included) may be coated with one or more functionalcoatings to modify the performance of privacy structure. Examplefunctional coatings include, but are not limited to, low-emissivitycoatings, solar control coatings, and photocatalytic coatings. Ingeneral, a low-emissivity coating is a coating that is designed to allownear infrared and visible light to pass through a pane whilesubstantially preventing medium infrared and far infrared radiation frompassing through the panes. A low-emissivity coating may include one ormore layers of infrared-reflection film interposed between two or morelayers of transparent dielectric film. The infrared-reflection film mayinclude a conductive metal like silver, gold, or copper. Advantageouslow-emissivity coatings include the LoE-180™, LoE-272™, and LoE-366™coatings available commercially from Cardinal CG Company of SpringGreen, Wis., U.S.A. A photocatalytic coating, by contrast, may be acoating that includes a photocatalyst, such as titanium dioxide. In use,the photocatalyst may exhibit photoactivity that can help self-clean, orprovide less maintenance for, the panes. Advantageous photocatalyticcoatings include the NEAT® coatings available from Cardinal CG Company.

As briefly mentioned above, the panes of transparent material formingprivacy glazing structure 12, whether implemented alone or in the formof a multiple-pane structure with a between-pane space, can includeelectrical connection regions to facilitate making electricalconnections with first electrode layer 20 and second electrode layer 22.FIG. 3 is a perspective view of an example edge configuration of privacyglazing structure 12 that includes electrical connection notches.

In the illustrated configuration of FIG. 3, first pane of transparentmaterial 14 defines a peripheral edge 60 and second pane of transparentmaterial 16 defines a peripheral edge 62. The peripheral edges of thepanes can constitute the outer boundary or periphery of each respectivepane. The first pane of transparent material 14 defines a first notch64, while the second pane of transparent material 16 defines a secondnotch 66. Each notch may be a cut out, void space, groove, recess, orother inwardly extending opening from the remainder of the peripheraledge. The first notch 64 can extend inwardly from the peripheral edgesurface 68 of privacy glazing structure 12 toward a geometric center offirst pane 14. The second notch can likewise extend inwardly from theperipheral edge surface 68 of privacy glazing structure 12 toward ageometric center of second pane 16. The peripheral edge surface 68 ofprivacy glazing structure 12 may be defined by the combined peripheraledge surfaces of first pane 14, second pane 16, and any gasket materialor edge sealant therebetween.

In general, first notch 64 may have a depth sufficient to expose theunderlying second electrode layer 22 carried by the underlying secondpane of transparent material 16. Likewise, the second notch 66 may havea depth sufficient to expose the underlying first electrode layer 20carried by the underlying first pane of transparent material 14.Accordingly, the notch on each pane can provide access to the electrodelayer carried by the opposite pane, thereby providing access for makingan electrical connection between the electrode layer and a power source.

Each notch 64, 66 may have a size sufficient to connect an electricalconductor to an underlying electrode layer within the notch. However,the size of each notch may be minimized to avoid encroaching into thesightline through privacy glazing structure 12 and limiting the amountof the structure consumed for electrical connections. In some examples,each notch may have a size greater than 10 square millimeters, such asgreater than 25 square millimeters, greater than 50 square millimeters,or greater than 100 square millimeters. Additionally or alternatively,the size of each notch may be less than 1000 square millimeters, such asless than 750 square millimeters, or less than 500 square millimeters.For example, the size of each notch may range from 5 square millimetersto 1000 square millimeters, such as from 25 square millimeters to 600square millimeters, from 50 square millimeters to 400 squaremillimeters, or from 100 square millimeters to 300 square millimeters.The first notch 64 may be the same size and/or shape as the second notch66 or may have a different size and/or shape.

In general, each notch 64, 66 can define any polygonal (e.g., square,hexagonal) or arcuate (e.g., circular, elliptical) shape, or evencombinations of polygonal and arcuate shapes. In some examples, firstnotch 64 and second notch 66 each have a curved shape extending fromfirst peripheral edge 60 and second peripheral edge 62, respectively,toward a center of the first and second panes. The curved shape may becharacterized by rounded edges that are devoid of sharp angles wheresurfaces converge that may provide stress fracture and breakagelocations. That being said, in other examples, first notch 64 and/orsecond notch may define a polygonal shape (e.g., rectangle, trapezoid)having sharp intersecting edges, and the disclosure is not limited inthis respect.

In some examples where first notch 64 and/or second notch 66 have acurved shape, the curved shape may include or be a semi-circular shapewhen looking at the outer face 24B and/or 26B of the first and/or secondpane. The peripheral edge of the first pane 14 and/or second pane 16 maybisect the semi-circular shape or may form a chord across thesemi-circular shape such that the semi-circular shape is not a full halfcircle.

FIGS. 4A-4D illustrate example cross-sectional shapes that may be usedfor first notch 64 and/or second notch 66 (e.g., in the cross-sectionalplane defining outer face 24B and/or 26B of first pane 14 and secondpane 16, respectively). In the example of FIG. 4A, a notch 70 having asemi-circular cross-sectional shape is illustrated. The semi-circularshape may be symmetric about a center line 72 that divides the notchinto two equal-area halves. In different examples, the semi-circularshape can be defined by a constant radius of curvature or a radius ofcurvature that varies across the shape. In some examples, the radius ofcurvature of notch 70 is greater than 1 mm, such as greater than 3 mm.If the radius of curvature of notch 70 is too small, there may be anincreased tendency for cracks or fractures at the notch.

The angle 74 at which the terminal edges 76 of notch 70 intersects theperipheral edge of the transparent pane can vary, e.g., depending on theshape of the notch. In general, the angle 74 may range from 10 degreesto 90 degrees, such as from 25 degrees to 75 degrees. FIG. 4Billustrates another example of notch 70 where the notch has a generallysemi-circular shape with terminal edges that flare outwardly to form anangle of intersection less than 45 degrees, such as less than 30degrees, or less than 15 degrees. The flare may be characterized by aninflection point along the perimeter of the notch where the notchtransitions from a lesser radius of curvature to a greater radius ofcurvature. Configuring a notch with a flared terminal edge may helpreduce edge stresses and/or provide additional opening space for routingwiring.

FIG. 4C illustrates an example asymmetrical configuration of a notch 70where the notch has a semi-circular portion 78 and a tail portion 80.The tail portion 81 extends parallel to the length of the peripheraledge and has a width toward the center of the transparent pane less thanthe width of the semi-circular portion 78. As a result, a first terminaledge 76A of the notch intersects the peripheral edge at an intersectionangle 74A greater than the intersection angle 74B at which a secondterminal edge 76B of the notch intersects the peripheral edge.Configured a notch with a tail portion running parallel to the length ofthe peripheral edge may be useful to route wiring extending from thenotch into the tail (e.g., and recessed relative to the peripheraledge).

FIG. 4D illustrates yet another example configuration of a notch 70 inwhich the notch has a dovetail shape. The dovetail shape may becharacterized as a mortise broader at its end than its base with flaringside edges. The dovetail shape may be useful to receive an insert coverafter making electrical connections to the underlying electrode layer.

While first notch 64 and/or second notch 66 have any suitable shape, insome examples, the notch(es) have a length greater than a width. FIG. 5illustrates an example notch 80 that can be used as first and/or secondnotch 64, 66. Notch 80 has a length 82 extending parallel to theperipheral edge 84 of the pane. Notch 80 also has a maximum width 86extending from peripheral edge 84 toward a center of the pane.Configuring notch 80 with a length 82 greater than a width 86 may beuseful to increase the area of the notch while limiting the extent towhich the notch creeps into the sightline through frame 30 (FIGS. 1 and2). In some examples, notch 80 has a length ranging from 10 mm to 100mm, such as from 20 mm to 50 mm. Additionally or alternatively, notch 80may have a width 86 less than 25 mm, such as less than 12 mm. Forexample, notch 80 may have a width 86 ranging from 3 mm to 9 mm. Asnoted, limiting the width 86 of notch 80 may be useful to prevent thenotch from being visible to an user looking through privacy glazingstructure 12 once installed in frame 30 and/or limit the extent to whichthe notch creeps above the bottom surface of the frame.

With further reference to FIG. 3, first pane of transparent material 14defines peripheral edge 60 and second pane of transparent material 16defines peripheral edge 62. When assembled into privacy glazingstructure 12, the peripheral edges 60, 62 of the two panes may be flushsuch that the resulting peripheral edge surface 68 of the structure isflush. The peripheral edges 60, 62 may be flush in that the surfaces ofthe edges defining the thickness of the panes may be substantiallyco-planar. For example, the peripheral edges 60, 62 may be sufficientlyaligned that the peripheral edge surface 68 of privacy glazing structure12 can be placed on a flat surface (e.g., of a conveyance roller orpiece of processing equipment) without causing the structure to tilttoward one side or the other because of unevenness of the two panes. Thedegree of offset between the peripheral edge 60 of first pane 14 andperipheral edge 62 of second pane 16, if any, may be within certainmanufacturing tolerances, such as less than 5 mm, less than 3 mm, lessthan 1 mm, or less than 0.5 mm. While electrical connection notches asdescribed herein may be beneficially implemented on a structure thatincludes opposed panes that are positioned to have flush, co-planarperipheral edges, it is contemplated that the notch structures can alsobe implemented in configurations where opposed panes are offset, or notflush.

Depending on the shape of first pane of transparent material 14 andsecond pane of transparent material 16, the panes may have multiplesides in which first notch 64 and second notch 66 may be formed. Forexample, first pane 14 and second pane 16 may each define a polygonalshape (e.g., square, rectangular, hexagonal), an arcuate shape (e.g.,circular, elliptical) shape, or combinations of polygonal and arcuateshapes (e.g., rectangle transitioning into a semi-circle). When firstpane 14 and second pane 16 are implemented using a polygonal shape, eachside of the polygon can define a peripheral edge surface in which firstnotch 64 and second notch 66, respectively, can be formed. In someexamples, the first notch 64 and second notch 66 are positioned on thesame side of the polygonal shape of first pane 14 and second pane 16,respectively. This can be useful to provide a common side of privacyglazing structure 12 for making electrical connections and routingwiring. In other configurations, however, the first notch 64 and secondnotch 66 may be positioned on different sides of first pane 14 andsecond pane 16, respectively.

In the example of FIG. 3, which is a partial perspective view of firstpane 14 and second pane 16, the panes each define a rectangular shapethat includes a first side 90 and a second side 92. The two sidesintersect at a corner 94. As shown in this example, first notch 64 andsecond notch 66 are both positioned on the first side 90 of the panes.

Positioning first notch 64 and second notch 66 in close proximity can beuseful to facilitate routing and positioning of wiring and electricalcontact hardware. In some configurations, first notch 64 and secondnotch 66 are positioned side-by-side to each other in either overlappingor non-overlapping configuration. In an overlapping configurationdiscussed in greater detail with respect to FIG. 6, adjacent terminaledges of the first and second notches may be crossed over each other. Bycontrast, in a non-overlapping configuration, adjacent terminal edges ofthe first and second notches may be offset from each other.

In the example illustrated in FIG. 3, first notch 64 defines a firstterminal edge 96A and a second terminal edge 96B. Similarly, secondnotch 66 defines a first terminal edge 98A and a second terminal edge98B. The terminal edges of the notches may be the location whereperipheral edges 60 and 62 intersect the boundaries of first and secondnotch 64, 66, respectively. A lateral separation distance 100 betweenadjacent first terminal edge 96A and of first notch 64 and firstterminal edge 98A of second notch 66 may be less than 100 mm, such asless than 50 mm, or less than 25 mm. For example, lateral separationdistance 100 may range from 1 mm to 25 mm, such as from 5 mm to 15 mm.

Independent of the positioning of the notches relative to each other, insome example, the terminal edge of each notch is separated from anearest corner or parallel peripheral edge surface by a minimumdistance. For example, in the configuration of FIG. 3, second terminalnotch 98B may be separated from corner 94 by the minimum distance. Theminimum distance may be at 50 millimeters, such as at least 75millimeters. Separating the terminal edges of the notches a thresholddistance from adjacent corner(s) can be helpful to prevent fractures orcracking.

As mentioned above, first notch 64 and second notch 66 may be positionedside-by-side to each other in an overlapping configuration. Whenarranged to overlap each other, a conduit or opening can be formedthrough the thickness of privacy glazing structure 12 where the notchesoverlap. FIG. 6 is a top view illustration showing an exampleconfiguration in which first notch 64 and second notch 66 overlap toform a conduit 102 through the region of overlap. The size of theconduit 102 may vary, e.g., depending on the size of first and secondnotches 64, 66 and the extent to which the notches overlap. In someexamples where privacy glazing structure 12 includes a conduit 102,however, the size of the conduit may range from 1 square millimeter to100 square millimeters, such as from 2 square millimeter to 25 squaremillimeter, or from 5 square millimeter to 20 square millimeter. Forexample, a ratio of the area of first notch 64 and/or second notch 66(including the area occupied by the conduit) divided by the area of theconduit may range from 5:1 to 20:1, such 10:1 to 15:1.

FIG. 7 is a side view illustrating an example arrangement of featureswhere first notch 64 overlaps with second notch 66. As shown, firstnotch 64 in privacy glazing structure 12 extends through the thicknessesof the first pane of transparent material 14, the first electrode layer20, and the electrically controllable optically active material 18. As aresult, access to the second electrode layer 22 on the inner face 26A ofthe second pane of transparent material 16 is provided from the outerface 24B of the first pane 14 via first notch 64. Similarly, the secondnotch 66 extends through the thicknesses of the second pane oftransparent material 16, the second electrode layer 22, and theelectrically controllable optically active material 18. As a result,access to the first electrode layer 20 on the inner face 24A of thefirst pane of transparent material 14 is provided from the outer face26B of the second pane 16.

Access to the first electrode layer 20 and second electrode layer 22 canbe provided by routing an electrical conductor through the outer faceand inner face of the opposite pane via a respective notch, therebyelectrically connecting the electrical conductor to the electrode layeron the inner face of the pane carrying the layer. In other examples, anelectrical conductor used to electrically connect the first electrodelayer 20 and/or second electrode layer 22 may be routed at leastpartially through conduit 102 to connect the electrical conductor to theelectrode layer.

The example of FIG. 7 illustrates wiring positioned in conduit 102 andelectrically connected to first electrode layer 20 and second electrodelayer 22. The wiring may be further connected to a power source, such asa driver or controller that provides power and/or control signals tocontrol optical active material 18. In the illustrated example, thewiring is illustrated as including a first wire 104A connected to thefirst electrode layer 20 and a second wire 104B connected to the secondelectrode layer 22. In general, the term wiring refers to any flexibleelectrical conductor, such as a thread of metal optionally covered withan insulative coating, a flexible printed circuit, a bus bar, or otherelectrical connector extending from outside the perimeter of first andsecond panes 14, 16 to the electrode layers carried by the panes viafirst and second notches 64, 66. It should be appreciated that wiringmay be used to connect first and second electrode layers 20, 22 to apower source in configurations where privacy glazing structure 12 doesnot include conduit 102 and this discussion is not limited to theexample configuration of FIG. 7

In configurations where privacy glazing structure 12 includesoverlapping notches to form conduit 102, the conduit can extend at leastpartially, and in the illustrated configuration fully, through thethickness of the first and second panes. Accordingly, conduit may definea first open end 106A through the outer face 24B of the first pane 14and a second open end 106B through the outer face 26B of the second pane16. In some examples, wiring is routed through both ends of the conduitto connect to first electrode layer 20 and second electrode layer 22. Inother examples, wiring is routing only through a single open end of theconduit. For example, in the example of FIG. 7, first wire 104A andsecond wire 104B both enter conduit 102 through the first open end 106Aof the conduit. First wire 104A bends approximately 90 degrees totransition from conduit 102 to first electrode layer 20. Second wire104B bends approximately 180 degrees to transition from conduit 102 tosecond electrode layer 22. This arrangement may allow wiring to be runon one side of the structure (e.g., the side having the conduit openingthrough which the wiring enters) but not the other side, making wiringrouting easier and less space intensive. When wiring is routed to enterthrough only a single opening of conduit 102, the conduit may not extendthrough the structure to define a second opening and/or the secondopening may be filled.

The wiring used to electrically connect the first and second electrodelayers 20, 22 to a power source can be mechanically affixed to theelectrode layers. In general, any type of mechanical fixation featurecan be used to secure the wiring to the electrode layers. As oneexample, each wire 104A, 104B may include a conductive clip (e.g.,alligator clip) that grabs the edge of pane within the notch. As anotherexample, each wire 104A, 104B may be bonded to a respective electrodelayer using a bonding agent. For example, each wire may be bonded usingultrasonic solder, an anisotrope conductive film (ACF), a conductiveepoxy, a pressure sensitive conductive transfer tape, or yet otherelectrically conductive bonding agent.

In different examples, the wiring may be attached directly to theelectrode layer, or the wiring may terminate in an electrode which, inturn, is attached to the electrode layer using any of the techniquesdiscussed above. In the example of FIG. 7, first wire 104A isillustrated as having a first electrode 108A attached at its terminalend, and second wire 104B is illustrated as having a second electrode108B attached at its terminal end. Each electrode may be formed of anelectrically conductive material (e.g., metal) and may have across-sectional area greater than that of the wire to which theelectrode is attached.

After suitably connecting the wiring to the electrode layers, firstnotch 64, second notch 66, and conduit 102 (when included) may be leftopen or may be filled. Filling the openings can provide additionalmechanical support for the electrical connections within the openings,electrical shielding, and/or protection from external elements such asmoisture. To fill the first and second notches 64, 66, a cover fillingmaterial may be introduced into the notches. In the example of FIG. 7, afirst cover material filling 110A is illustrated as filling first notch64 and a second cover material 110B is illustrated as filling secondnotch 66. First cover filling material 110A and second cover fillingmaterial 110B may be the same material or different materials. Further,although no illustrated in FIG. 7, conduit 102 may also be filled with acover filling material which, again, may be the same material as firstcover filling material 110A and/or second cover filling material 110B ormay be a different material.

In some examples, the first cover filling material 110A and/or secondcover filling material 110B is or includes a polymeric sealant, such asa conformal coating or a potting/encapsulant material that is flowablyfilled into the notch(es) and set within the notches. Example polymericmaterials that may be used include silicone-based materials, epoxy-basedmaterials, acrylate-based materials, and urethane-based materials.

Additionally or alternatively, a cover plate may be installed tofunction as the first cover filling material 110A and/or second coverfilling material 110B. The cover plate may be rigid (e.g., substantiallyunbendable under hand pressure) or flexible. The cover plate may have afootprint (e.g., size and/or shape) mirroring the notch into which thecover plate is to be inserted. In some examples, a polymeric sealant isdeposited in the notch to be filled and a cover plate inserted into thenotch over the sealant. The cover plate may have a thickness effectiveso that, once installed into the notch, the cover plate is substantiallyflush with the outer surface of the pane into which the cover plate isinserted (e.g., +/−0.2 mm). Further, the cover plate may have a lengthand width effective so the peripheral edge of the cover plate is flushwith the reminder of the peripheral edge of the privacy structure.

In some examples, the cover plate may have a thickness less than orequal to the thickness of the pane defining the notch into which thecover plate is to be inserted. For example, the cover plate may have athickness that falls within a range from being 0.1 mm thinner than thepane defining the notch into which the cover plate is to be inserted to0.5 mm thinner. In some examples, first pane 14 and second pane 16 mayhave a thickness ranging from 2 mm to 6 mm. Accordingly, in theseexamples, the cover plate may have a thickness less than 6 mm, such asless than 3 mm, or less than 2 mm.

Example materials that may be used to form a rigid cover plate includeceramic materials and glass materials. For example, the cover plate maybe fabricated from soda lime silica glass, sodium borosilicate glass,aluminosilicate glass, or fused silica. In one example, the cover plateis formed of the same material (and thereby has substantially the sameoptical characteristics) as the pane defining the notch into which thecover plate is to be inserted. Example materials that may be used toform a flexible cover plate include polymeric films, such aspolyethylene terephthalate (PET), polyvinyl chloride (PVC), andpolyurethane.

When used, the first cover filling material 110A and/or second coverfilling material 110B may electrically isolate the underlying electricalconnection(s) and protect the connections against moisture ingress.Accordingly, the cover filling material may have a surface electricalconductivity of less than 1 Mohm and/or have a moisture transmission ofless than 1 g/square meter/day at 95% relative humidity and 20 degreesCelsius.

To help hold the cover plate in the notch into which the cover plate isinserted, the wall surfaces of the notch may be sloped from the outerface to the inner face. That is, rather than forming the wall surfacesbounding the notch to extend perpendicularly (zero degree angle) fromthe outer face to the inner face, the wall surfaces may extend at anon-zero degree angle with respect to normal. When so configured, thenon-zero degree angle may range from 15 to 75 degrees relative tonormal. Sloping the wall surfaces may help form a tongue-and-groovestructure with corresponding sloped wall surfaces of the cover plate,helping the cover plate to nest and be secured in the notch. FIGS. 8Aand 8B illustrate example sloped notch wall surfaces that may be used ona notch according to the disclosure. The examples show the wall surfacesof first notch 64 sloping at an angle 112 relative to normal from theouter face 24B to the inner face 24A.

To bond and/or seal the first pane of transparent material 14 to thesecond pane of transparent material 16 with optically active material 18between the two panes, a seal may be positioned between the two panes.The seal may be implemented using one or more polymeric sealants thatare positioned to extend around the perimeter of the first pane oftransparent material 14 and the second pane of transparent material 16,e.g., adjacent to and/or in contact with the peripheral edge surface 68.The sealant(s) may bond the first pane of transparent material 14 to thesecond pane of transparent material 16 about their perimeter, e.g., toprevent ingress or egress of liquid from the region bounded by thesealant(s). For example, the sealants may hold liquid optically activematerial 18 between the panes within the region bounded by thesealant(s) and/or inhibit external moisture from reaching the opticallyactive material.

Without wishing to be bound by any particular theory, it is has beenfound in some applications that positioning the sealant over theelectrode layers of the optical structure such that electricity isconveyed through the seal during operation of the structure has atendency to accelerate degradation of the sealant. Accordingly, in someconfigurations, the electrode layers are offset from the peripheral edgeof the transparent panes about which the sealant extends. For example,the electrode layers may be removed (e.g. via grinding or laserablation) such that the perimeter region over which the sealant extendsis devoid of one or both electrode layers and/or the electrode layersare otherwise deactivated in the region. Alternatively, the electrodelayers may be deposited on the panes so that the electrode layers do notextend over the surface where the sealants are to be deposited.

FIGS. 9A and 9B are views of the inner surface 24A and 26A of the firstand second panes of transparent material 14 and 16, respectively,showing example electrode layer arrangements. As shown in FIG. 9A, firstelectrode layer 20 is offset from the perimeter around the pane overwhich the seal is to be deposited. In particular, in the illustratedexample, first electrode layer 20 is offset a distance 120A from theperipheral edge 60 of the first pane. Similarly, as shown in FIG. 9B,second electrode layer 22 is offset from the perimeter around the paneover which the seal is to be deposited. In the illustrated example,second electrode layer 22 is offset a distance 120B from the peripheraledge 62 of the second pane. Because electricity will not pass betweenthe first and second pane 14, 16 in the region where the first electrodelayer 20 and/or second electrode layer 22 is offset (e.g., missing,devoid), electricity will not transfer through sealant positioned inthis region during operation of the device. While the offset distances120A and 120B may vary, e.g., depending on the width of sealant to bedeposited, in some examples, one or both distances may range from 1 mmto 25 mm, such as from 5 mm to 15 mm.

While offsetting one or both electrode layers may be useful to helpprevent electricity from flowing through a perimeter seal duringoperation, the electrode layers may nevertheless extend under the regionaccessible by an overlying notch in order to make electricalconnections. To facilitate these electrical connections where anelectrode layer is offset from the peripheral edge, the electrode layermay have a contact portion that extends towards and/or to the peripheraledge from a remainder of the offset electrode layer. The contact portioncan be sized and shaped to underlay the region of the pane exposed by anoverlying notch for making electrical connections.

In the example of FIG. 9A, first electrode layer 20 includes a firstcontact portion 122A extending from peripheral edge 60 of first pane 14to a remainder of the first electrode layer that is offset from theperipheral edge distance 120A. First contact portion 122A is configuredto underlie second notch 66, when the first and second panes areassembled together with optically active material 18 positioned betweenthe panes. As also shown in the example of FIG. 9B, second electrodelayer 22 includes a second contact portion 122B extending fromperipheral edge 62 of the second pane 16 to a remainder of the secondelectrode layer that is offset from the peripheral edge distance 120B.Second contact portion 122B is configured to underlie first notch 64,when the first and second panes are assembled together with opticallyactive material 18 positioned between the panes.

In general, first contact portion 122A and second contact portion 122Bcan define any polygonal (e.g., square, rectangular, hexagonal) orarcuate (e.g., circular, elliptical) shape. The size of the contactportions may vary, e.g., depending on the size of the notches. In someexamples, each contact portion may have a size greater than 10 squaremillimeters, such as greater than 25 square millimeters, greater than 50square millimeters, or greater than 100 square millimeters. Additionallyor alternatively, the size of each contact portion may be less than 1000square millimeters, such as less than 750 square millimeters, or lessthan 500 square millimeters. For example, the size of each contactportion may range from may range from 5 square millimeters to 1000square millimeters, such as from 100 square millimeters to 800 squaremillimeters, from 250 square millimeters to 600 square millimeters. Thefirst contact portion 122A may be the same size and/or shape as thesecond contact portion 122B or may have a different size and/or shape.

Electrical connection configurations according to the disclosure can beused to provide electrical control over an electrically controllableoptically active layer 18. While the foregoing description has generallydescribed a privacy structure having one pair of notches (one on eachpane), a structure according to the disclosure may have multiple pairsof notches. In different configurations, privacy structure 12 can beconfigured as a controllable monopixel structure or a multi-pixelstructure. In a monopixel configuration, the entire active area overwhich optically active material 18 is positioned transitions from onevisibility state to another visibility state. Accordingly, a single pairof notches may be sufficient to control the single pixel, althoughmultiple pairs of notches with independent electrical connections can beprovided for design redundancy. In a multi-pixel configuration, theactive area over which optically active material 18 is positioned may bebroken into different independently controllable regions, e.g., with theelectrode layer being scribed or broken to separate differentcontrollable regions. Each controllable region may have at least onepair of notches to provide independent electrical connection and controlto each controllable region, or pixel, of the privacy structure.

In still other examples, an electrical connection configurationaccording to the disclosure may be provided by a single notch ratherthan using multiple notches. In a single notch arrangement, twoelectrode pads or contact portions may be provided within the notch. Theelectrical contact portions within the single notch may be electricallyisolated from each other and connected to different electrode layers.FIGS. 10A and 10B are top and side views, respectively, showing anexample single notch electrical configuration.

As shown in the illustrated example, the first pane of transparentmaterial 14 defines a peripheral edge 62 and a notch 64. Notch 64provides access to an underlying second pane of transparent material 16that does not include a second electrical connection notch associatedwith notch 64 in the first pane. First pane of transparent material 14carries first electrode layer 20, while second pane of transparentmaterial 16 carries second electrode layer 22. Two electrode layers orcontact pads 150 and 152 are provided on second pane of transparentmaterial 16 and accessible via notch 62. The two electrode layers orcontact pads may be electrically isolated from each other, e.g., byscribing second electrode layer 22 to form one pad 150 that iselectrically isolated from the remainder of the layer and a second pad152 that is electrically coupled to the remainder of the layer.Accordingly, an electrically isolated perimeter 154 may be establishedaround the contact pad 150 that is electrically isolated from thereminder of the electrode layer carried by second pane of transparentmaterial 16. An insulating layer, such as an insulating adhesive 158 canbe positioned between first electrode layer 20 and second electrodelayer 22 in the region adjacent notch 64 to electrically isolate the twolayers from each other.

To electrically connect first electrode layer 20 using notch 64, aconnective crossover member 156 can be provided to electrically couplecontact pad 150 to the electrode layer. The conductive crossover member156 may be any electrically conductive structure, such as anelectrically conductive layer (e.g., electrical pad), wire, conductiveconduit, or other electrically conductive structure. Conductivecrossover member 156 is electrically coupled to first electrode layer20. In operation, electricity delivered to contact pad 150 is conveyedthrough conductive cross-over member 156 to first electrode layer 20.While conductive crossover 154 is illustrated as being a physicallyseparate structure than contact pad 150 and first electrode layer 20, itshould be appreciated that the conductive crossover may be an extensionof or integrally formed with one or both structures.

To deliver electricity to first electrode layer 20 and second electrodelayer 22 via single notch 64, wiring may extend from outside of theprivacy structure and electrically connect to the first and secondelectrode layers in the notch. In the illustrated example, the wiring isillustrated as including a first wire 104A connected to the firstelectrode layer 20 and a second wire 104B connected to the secondelectrode layer 22. The wiring may be further connected to a powersource, such as a driver that provides power and/or control signals tocontrol optical active material 18.

Notches according to the disclosure have generally been illustrated asdefining a cutout extending from an outer surface of a pane oftransparent material to an inner surface of the pane, such as from outersurfaces 24B and 26B to inner surfaces 24A and 26A of the first andsecond panes of transparent material, respectively. A notch according tothe disclosure may be formed from an edge of a pane of material inwardlytoward a center of the pane of transparent material without extendingthrough an entire thickness of the material.

FIGS. 11A-11C illustrate example assembly steps for forming a notch inan edge of a pane of transparent material that does not extend throughthe entire thickness of the material. As shown in the illustratedexample, a notch 64 is formed in a first pane of transparent materialthat does not extend through the entire thickness of the material.Rather, notch 64 cuts into the inner surface 24A of the first pane oftransparent material without extending all the way through to the paneto the outer surface 24B. For example, notch 64 can extend from an outerfacing edge of the pane of transparent material to a terminal wallinside of the pane of transparent material that bounds the notch.

As shown in FIG. 11C, an electrode 160 can be positioned in notch 64from the side edge of the pane of transparent material rather thanthrough the outer face of the pane of transparent material. Electrode160 can provide electrical communication with an electrode layer onsecond pane of transparent material 16. Electrode 160 can extend outfrom the side edge of the pane of transparent material for connection toa power source.

Notch 64 in the example of FIGS. 11B and 11C can have a depth anddimensions as discussed above with respect to other notch configurationsdescribed herein. The thickness of notch 64 in embodiments where thenotch does not extend through the entire thickness of the pane may beless than or equal to one half the thickness of the pane in which thenotch is formed, such as a thickness ranging from 1/10 to ⅓ thethickness of the pane in which the notch is formed.

In some configurations, electrode 160 is configured to wrap around thesecond pane of transparent material in a generally U- or C-shapedconfiguration. When so configured, second pane of transparent material16 may or may not include a relief notch in which a portion of theelectrode wrapping about outer surface 26B of the pane is positioned.

For example, FIGS. 12A-12C illustrate example assembly steps for forminga notch and a relief notch in an edge of a pane of transparent materialthat does not extend through the entire thickness of the material. Theassembly steps illustrated in FIGS. 12A-12C are the same as thoseillustrated in FIGS. 11A-11C except that the second pane of transparentmaterial 16 also includes a relief notch 162. As shown, relief notch 162can be formed in the outer surface 26B extending toward the innersurface 26A of the second pane of transparent material 16. Relief notch162 may have the same size and/or shape as notch 64 or may have adifferent size and/or shape. Relieve notch 162 can provide a cavity forreceiving a portion of electrode 160 extending over and/or conforming tothe side edge of the pane in which the notch is formed. In someexamples, the edge itself is grooved in the region of electrode 160relative to a remainder of the edge such that the top edge of theelectrode is substantially flush (or even recessed) relative to thereminder of the edge.

Although not illustrated in FIGS. 11A-11C and 12A-12C, first pane oftransparent material 14 and second pane of transparent material 16 may anotch 64 and/or relief notch 162 on opposite surfaces from the surfacesin which the notches are illustrated as being formed. These oppositefacing notch(es) can be used to electrically connected the electrodelayer on the first pane of transparent material 14 with an electrode 160similar to the configuration illustrated for electrically connecting theelectrode layer on the second pane of transparent material. Additionallyor alternatively, one or both electrode layers may be electricallyaddressed through multiple notches (e.g., two, three, or more notches)arranged in series with multiple electrically connected electrodes. Anexample of such a configuration is illustrated in FIGS. 13A-13C.Providing multiple electrical connection notches can be useful toprovide redundant electrical connections in the event one electricalconnection fails during the service life of the device.

Various examples have been described. These and other examples arewithin the scope of the following claims.

1. A privacy glazing structure comprising: a first pane of transparentmaterial having an inner face, an outer face, and a peripheral edge; asecond pane of transparent material having an inner face, an outer face,and a peripheral edge; a first electrode layer on the inner face of thefirst pane of transparent material; a second electrode layer on theinner face of the second pane of transparent material; an electricallycontrollable optically active material positioned between the firstelectrode layer on the inner face of the first pane of transparentmaterial and the second electrode layer on the inner face of the secondpane of transparent material; wherein the first pane of transparentmaterial is generally parallel to the second pane of transparentmaterial to form a cavity therebetween containing the electricallycontrollable optically active material, and the peripheral edge of thefirst pane of transparent material is aligned with the peripheral edgeof the second pane of transparent material to provide a flush edgesurface, the first pane of transparent material defines a first notchproviding access to the second electrode layer on the inner face of thesecond pane of transparent material, the second pane of transparentmaterial defines a second notch providing access to the first electrodelayer on the inner face of the first pane of transparent material, andthe first notch overlaps the second notch to define a conduit extendingthrough the first pane and the second pane.
 2. The structure of claim 1,wherein the first notch extends from the peripheral edge of the firstpane toward a center of the first pane a distance less than 12 mm, andthe second notch extends from the peripheral edge of the second panetoward a center of the second pane a distance less than 12 mm.
 3. Thestructure of claim 1, wherein the first notch and the second notch eachhave a size within a range from 50 square millimeters to 400 squaremillimeters.
 4. The structure of claim 1, wherein the first notch andsecond notch have a length along the peripheral edge of the first paneand the peripheral edge of the second pane, respectively, greater than awidth extending toward a center of the first pane and the second pane,respectively.
 5. The structure of claim 1, wherein: the first notchextends through thicknesses of the first pane of transparent material,the first electrode layer, and the electrically controllable opticallyactive material to provide access to the second electrode layer on theinner face of the second pane of transparent material from the outerface of the first pane; and the second notch extends through thicknessesof the second pane of transparent material, the second electrode layer,and the electrically controllable optically active material to provideaccess to the first electrode layer on the inner face of the first paneof transparent material from the outer face of the second pane.
 6. Thestructure of claim 1, wherein the first pane of transparent material andthe second pane of transparent material each have a polygonal shapehaving a plurality of sides, and the first notch and the second notchare on a same side of the plurality of sides.
 7. The structure of claim1, wherein adjacent terminal edges of the first notch and the secondnotch are laterally offset from each other a distance ranging from 1 mmto 25 mm.
 8. The structure of claim 1, further comprising wiringpositioned in the conduit connecting the first electrode layer and thesecond electrode layer to a power source.
 9. The structure of claim 8,wherein: the wiring comprises a first wire connected to the firstelectrode layer and a second wire connected to the second electrodelayer, the conduit has a first open end through the outer face of thefirst pane and a second open end through the outer face of the secondpane, and the first wire and the second wire both enter the conduitthrough the first open end of the conduit.
 10. The structure of claim 9,further comprising a first electrode attached to the first wire and asecond electrode attached to the second wire.
 11. The structure of claim10, wherein the first electrode is bonded to the first electrode layerand the second electrode is bonded to the second electrode layer. 12.The structure of claim 1, wherein the conduit has a size ranging from 2square millimeters to 25 square millimeters.
 13. The structure of claim1, wherein the first notch and the second notch each have a curved shapeextending from the peripheral edge of the first pane and the peripheraledge of the second pane, respectively, toward a center of the first paneand the second pane, respectively.
 14. The structure of claim 13,wherein the curved shape comprises a semi-circle having a radius ofcurvature less than 3 mm.
 15. The structure of claim 1, wherein thefirst pane of transparent material and the second pane of transparentmaterial each have a polygonal shape having a plurality of sides joinedat corners, and a distance between a terminal edge of the first notchadjacent a nearest corner and a terminal edge of the second notchadjacent a nearest corner is at least 75 millimeters.
 16. The structureof claim 1, wherein the first notch and the second notch are defined bywall surfaces of the first pane and second pane, respectively, thatslope at a non-zero degree angle from the outer face to the inner face.17. The structure of claim 1, further comprising a first cover materialfilling the first notch and a second cover material filling the secondnotch.
 18. The structure of claim 17, wherein the first cover materialand the second cover material are each elected from the group consistingof a polymeric sealant, a polymeric film a rigid plate, and combinationsthereof.
 19. The structure of claim 18, wherein the first cover materialand the second cover material each comprise a rigid plate formed forglass having a footprint mirroring the first notch and the second notch,respectively.
 20. The structure of claim 19, wherein the rigid plateforming the first cover material has a thickness less than a thicknessof the first pane, and the rigid plate forming the second cover materialhas a thickness less than a thickness of the second pane.
 21. Thestructure of claim 1, wherein the first pane and the second pane areeach fabricated from float glass and have a thickness ranging from 2 mmto 6 mm.
 22. The structure of claim 1, further comprising a sealantextending around a perimeter of the first pane of transparent materialand the second pane of transparent material and bonding the first paneof transparent material to the second pane of transparent material. 23.The structure of claim 22, wherein: the first electrode layer if offsetfrom the perimeter around the first pane of transparent material overwhich the seal is in contact such that electricity does not transferfrom the first electrode layer through the seal, and the secondelectrode layer if offset from the perimeter around the second pane oftransparent material over which the seal is in contact such thatelectricity does not transfer from the second electrode layer throughthe seal.
 24. The structure of claim 23, wherein the first electrodelayer is offset a distance ranging from 5 mm to 15 mm from theperipheral edge of the first pane, and the second electrode layer isoffset a distance ranging from 5 mm to 15 mm from the peripheral edge ofthe second pane.
 25. The structure of claim 24, wherein: the firstelectrode layer includes a first contact portion extending from theperipheral edge of the first pane to a remainder of the first electrodelayer that is offset from the peripheral edge, the first contact portionunderlying the second notch, and the second electrode layer includes asecond contact portion extending from the peripheral edge of the secondpane to a remainder of the second electrode layer that is offset fromthe peripheral edge, the second contact portion underlying the firstnotch.
 26. The structure of claim 1, wherein the electricallycontrollable optically active material is a liquid crystal materialhaving a light transmittance that varies in response to application ofan electrical field.
 27. The structure of claim 1, further comprising: athird pane of transparent material generally parallel to the first paneof transparent material and the second pane of transparent material, anda spacer positioned between the third pane of transparent material andthe first pane of transparent material to define a between-pane space,the spacer sealing the between-pane space from gas exchange with asurrounding environment and holding the first pane of transparentmaterial a separation distance from the third pane of transparentmaterial.
 28. A privacy glazing structure comprising: a first pane oftransparent material having an inner face and an outer face; a secondpane of transparent material having an inner face and an outer face; afirst electrode layer on the inner face of the first pane of transparentmaterial; a second electrode layer on the inner face of the second paneof transparent material; an electrically controllable optically activematerial positioned between the first electrode layer on the inner faceof the first pane of transparent material and the second electrode layeron the inner face of the second pane of transparent material; a sealantextending around a perimeter of the first pane of transparent materialand the second pane of transparent material and bonding the first paneof transparent material to the second pane of transparent material,wherein the first electrode layer if offset from the perimeter aroundthe first pane of transparent material over which the seal is in contactsuch that electricity does not transfer from the first electrode layerthrough the seal, and the second electrode layer if offset from theperimeter around the second pane of transparent material over which theseal is in contact such that electricity does not transfer from thesecond electrode layer through the seal.
 29. The structure of claim 28,wherein: the first pane of transparent material has a peripheral edge;the second pane of transparent material has a peripheral edge; the firstelectrode layer is offset a distance ranging from 5 mm to 15 mm from theperipheral edge of the first pane, and the second electrode layer isoffset a distance ranging from 5 mm to 15 mm from the peripheral edge ofthe second pane.
 30. The structure of claim 28, wherein: the first paneof transparent material has a peripheral edge; the second pane oftransparent material has a peripheral edge; the first electrode layerincludes a first contact portion extending from the peripheral edge ofthe first pane to a remainder of the first electrode layer that isoffset from the peripheral edge, and the second electrode layer includesa second contact portion extending from the peripheral edge of thesecond pane to a remainder of the second electrode layer that is offsetfrom the peripheral edge.
 31. The structure of claim 28, wherein theelectrically controllable optically active material is a liquid crystalmaterial having a light transmittance that varies in response toapplication of an electrical field.